Need help with lens problem

Spott

Problem,
Occasionally when my Nikon D300 meters off the lens does not register it's correct settings when it "wakes up".
Lens,
AF Zoom-NIKKOR 24-85mm f/2.8-4D IF
Example,
Camera on tripod, set to any focal length other than 85mm, at any f-stop (f4 or higher). As long as camera does not go into "stand-by" mode it will keep settings. However, if I leave the camera untouched long enough for it to go into "stand-by" mode (say to change lighting, backdrop, subject) when I "wake-up" the camera it reads as if the lens is at 85mm no matter what the actual focal length is. If the f-stop was set to under f4 then the camera says the lens is at f4. All the other settings register accurately. The resulting image is a stop or two brighter than the previous one with the correctly registering focal length.
Furthermore, when the lens is set to minimum focal length (28mm) it will not always go to the widest aperture (f2.8). (The best I can count on is f4). I learned one day that when it acts up like this a rapid zoom in / zoom out seems to almost always provide a fix long enough to get the shot.

Six months ago this was a every once in a while issue that I thought to be operator error. Now it is more common & I know its not my doing. I have tried cleaning all the contacts & done everything shy of opening up the lens myself (no way in hell).
Why is this happening?
What are my options for correcting this problem?

time2smile

First of all Welcome..

Please dont consider the ? an insult, just some fact gathering.

"If the f-stop was set to under f4 then the camera says the lens is at f4."

Are you setting the Fstop on the lens, it should be locked to F22.

"All the other settings register accurately. The resulting image is a stop or two brighter than the previous one with the correctly registering focal length."

Active Dlighting can do this, if I understand correctly, try to turn it off and see if the results change.

"Furthermore, when the lens is set to minimum focal length (28mm) it will not always go to the widest aperture (f2.8). "

Are you in A priority when you try this, P and S will not always go to F2.8, especially if you have AUTO ISO on.

I dont have a D300 just a D90, but lets see if we can get the ball rolling to get answers to your questions,
So if I understand correctly the camera act erratically only after it has gone into sleep mode, and if you zoom in and, it starts to function correctly again.

Have you tried different lens on it? Or id it just with the 24-85?

good luck

Qarik

hmm..so the lens is registering the wrong focal length. How do you know? I don't seem to recall seeing any focal length info that is readily viewable pre-shot. Are you noticing the exif data is incorrect post shot? Also even if the focal length is not correct..this in and by itself should not effect exposure.

The incorrect aperture and being unable to get to < f/4 is more troubling. From what you described it seem like something in the lens is degrading over time. I assume you do not see this with other lens?

Have you tried cleaning your camera body and lens contact points? I recall ziggy suggested taking a pencial erasor and gently scrubbing can do the trick. If this doesn't work and you are using the lens in critical situations..get it serviced.

ziggy53

Do you have other lenses?

Have you tried a different battery?

Does this happen in any particular environmental situation? (Camera is warm or camera is cold, for instance.)

Spott

First off, nothing was interpreted as insult.


More facts



Aperture ring is locked at f/22. Ring has been locked, unlocked & rotated to both ends (f2.8 - 22) in attempts to locate problem source.

F-stop is being set on body (sub-command dial)

Exposure mode is manual 100% of the time

Problem occurs when all settings are reset to Nikon default.

Multiple body batteries.

Consistent so far in environments of problem occurring. (studio, outdoor, fast action, low light, warm or cool.)

Example;
I decide I want 1/100, f-2.8, at 24mm, dial that in. With my lens at 24mm the aperture (changed on body) to f2.8 should maintain those setting unless I change them. What happens is I get 1/00 f4 in the display, then in the exif it says 85mm (instead of 24) along with 1/100 f4 (even though I set f2.8). If I zoom out then in once rapidly I can get the aperture to come back down to f2.8. Then at its whim back up to f4.

Odd exception - If Aperture is set to f4.5 or higher & this problem happens, the correct aperture will be recorded but the focal length is 85mm in the exif. No matter what it was really at.


Regretfully this is my only lens that I have available. Im tempted to go to the camera shop just to diagnose symptoms (feels kinda rude though).


When the problem started I could keep it under control by keeping the camera from going into sleep mode, now, preventing sleep does not always work but the zoom in/out does.

I have cleaned the camera & lens to the extent I am proficient (the basics). Whatever the problem is I think its needs to go to a pro shop for repair. This lens is my workhorse being my only worthwhile lens & gets a lot of use. May just be time for a tune up. But, if that is the case why is this problem so uncommon?

This link has two images shot a few seconds apart that illustrate the problem perfectly. The 1st is recorded correctly & the 2nd is after the problem. (any other critique is welcomed & appreciated as well).

http://spott.smugmug.com/Other/Technical/12197458_9Cbnr#868345422_U7KQx


Thank you
Spott

time2smile

The EXIF data not showing up, your camera info may be set to no.

I would say you need to try another lens, and see if the lens data transfers to the camera correctly. If there is a real camera store in your area, just bring the camera in and say you want to try a few lens out to see how you like them, they may even have a few used ones, and find a great deal on top of it all. Real old time shops love to have a current or future D300 customer they can help, not rude...

At this point, I'm not going to guess if its the lens or the body, but something does sound wrong. did you check Nikon web site for FAQ and maybe even a firmware update. I did notice some improvements in firmware V1.10, thats if you still have V1.0 in the camera. Heres a link if you didn't check this out already.
http://support.nikontech.com/app/answers/detail/a_id/16149/session/L2F2LzEvc2lkLzlNeXNDKl9q

Good Luck and keep us posted...

ziggy53

It does seem that the lens is not communicating properly with the camera body. While it could be either end causing the mis-communication, the fact that a simple zoom adjustment seems to cure the problem might indicate more responsibility towards the lens.

If, instead of adjusting the zoom, you simply grab hold of the lens body and wiggle it rotationally, does it have the same effect in causing the body to recognize the lens?

hillsidekim

I agree with the consensus that it is a problem with lens/body communication. I know you said you cleaned the contacts, but there is a product on the market called DeoxIT which is specialized for cleaning, enhancing and protecting electronic contacts. I got mine at Radioshack but have heard it's available at Best Buy also. Spray a little on a q tip and clean the contacts on both the camera and the lens again thoroughly and see if that may not take care of the problem.
Good luck,
Kim

time2smile

hillsidekim wrote: »

I agree with the consensus that it is a problem with lens/body communication. I know you said you cleaned the contacts, but there is a product on the market called DeoxIT which is specialized for cleaning, enhancing and protecting electronic contacts. I got mine at Radioshack but have heard it's available at Best Buy also. Spray a little on a q tip and clean the contacts on both the camera and the lens again thoroughly and see if that may not take care of the problem.
Good luck,
Kim

Welcome Kim, thanks for your input...